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My daily commute takes my trough the mountains and after coasting down the mountain for about 5 miles my cars smokes very bad once I hit the gas again. It's a large and embarrassing plume of smoke out the tailpipe that continues until I reach cruising speed of about 65 mph. I smell oil when it does it. Sometimes when I step on the gas hard I can see a little smoke even if I haven't been coasting down hill. Compression ranges from 139-148. No coolant in oil or visa versa. The car burns oil, about 1 qt every 500-700 miles. Is my compression low enough for it to be worn rings or its it something else? I would guess the engine has at least 200,000 miles on it.
 

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I am only guessing, that it is worn oil-control rings. Normally any older car will smoke after coasting down a long downhill, but with our cars having catalytic converters, the converter usually burns up the hydrocarbons before they get out the exhaust pipe.
Your oil consumption would be fairly normal for an engine with worn rings - though Im inclined to put the blame more on oil control rings that are either worn, or sort ot stuck in the grooves.


Your compression figures are a litele bow, but that could be because you dindt hold the throttle open, or didnt let the engine crank over for about 6 compression strokes.

I believe the engine stops firing the injectors, when you are coasting downhill with your foot off the gas, and the engine is spinning faster than about 1400 rpm. Due to the distance you are coasting, it might let the cylinders and combustion chamber cool off quite a bit. I know that with my 5-speed Escort, the injectors are not firing when I have my foot off the gas, and am coasting downhill, with the engine turning faster than 1400 rpm.
 

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Yep engine braking puts vacuum in the cylinders. Worn rings will allow oil to be sucked up into the combustion chamber, building up until you finally get to the bottom of the incline and add some fuel to begin burning it off.
 
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Yep engine braking puts vacuum in the cylinders. Worn rings will allow oil to be sucked up into the combustion chamber, building up until you finally get to the bottom of the incline and add some fuel to begin burning it off.
That's classic valve stem seals too.

From lx experience, that could be warming up a puddle of oil in the intake too, though that's an lx example. I'm just being contrary.
 

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Hi; i changed sleeves; pistols and rings but blue smoke is coming out when going down the hill; when i go up the hill oil and blue smoke come out the breather pipe in my truck; cylinder head is coming from engineers; will appreciate any ideas what may be the cause.
 

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Reportedly, synthetic oil produces less visible smoke so a change to that might be worth a try. If you wait for the sales, it seems to be not too expensive.

The injectors shutting down below 1400 rpm is a feature of the engine control. But they actually stay off until the rpms drop to 1200 or so (at least on my car). The reason I know is that at one point my mechanical pressure gauge was "telegraphing" the engine sounds quite clearly. I could hear the light ticking of the injectors come on and off at around that rpm.
 
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